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Commit b3ea36b7 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'perf-fixes-for-linus' of... 

Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  kprobes/x86: Fix the return address of multiple kretprobes
  perf tools: Fix build error on read only source.
  perf, x86: Fix Intel-nhm PMU programming errata workaround
parents 763008c4 737480a0

arch/x86/kernel/cpu/perf_event_intel.c

+63 −18
Original line number Diff line number Diff line
@@ -491,33 +491,78 @@ static void intel_pmu_enable_all(int added) 
 *   Intel Errata AAP53  (model 30)

 *   Intel Errata BD53   (model 44)

 *

 * These chips need to be 'reset' when adding counters by programming

 * the magic three (non counting) events 0x4300D2, 0x4300B1 and 0x4300B5

 * either in sequence on the same PMC or on different PMCs.

 * The official story:

 *   These chips need to be 'reset' when adding counters by programming the

 *   magic three (non-counting) events 0x4300B5, 0x4300D2, and 0x4300B1 either

 *   in sequence on the same PMC or on different PMCs.

 *

 * In practise it appears some of these events do in fact count, and

 * we need to programm all 4 events.

 */

static void intel_pmu_nhm_enable_all(int added)

static void intel_pmu_nhm_workaround(void)

{

	if (added) {

	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);

	static const unsigned long nhm_magic[4] = {

		0x4300B5,

		0x4300D2,

		0x4300B1,

		0x4300B1

	};

	struct perf_event *event;

	int i;



		wrmsrl(MSR_ARCH_PERFMON_EVENTSEL0 + 0, 0x4300D2);

		wrmsrl(MSR_ARCH_PERFMON_EVENTSEL0 + 1, 0x4300B1);

		wrmsrl(MSR_ARCH_PERFMON_EVENTSEL0 + 2, 0x4300B5);

	/*

	 * The Errata requires below steps:

	 * 1) Clear MSR_IA32_PEBS_ENABLE and MSR_CORE_PERF_GLOBAL_CTRL;

	 * 2) Configure 4 PERFEVTSELx with the magic events and clear

	 *    the corresponding PMCx;

	 * 3) set bit0~bit3 of MSR_CORE_PERF_GLOBAL_CTRL;

	 * 4) Clear MSR_CORE_PERF_GLOBAL_CTRL;

	 * 5) Clear 4 pairs of ERFEVTSELx and PMCx;

	 */



		wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0x3);

		wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0x0);

	/*

	 * The real steps we choose are a little different from above.

	 * A) To reduce MSR operations, we don't run step 1) as they

	 *    are already cleared before this function is called;

	 * B) Call x86_perf_event_update to save PMCx before configuring

	 *    PERFEVTSELx with magic number;

	 * C) With step 5), we do clear only when the PERFEVTSELx is

	 *    not used currently.

	 * D) Call x86_perf_event_set_period to restore PMCx;

	 */



	/* We always operate 4 pairs of PERF Counters */

	for (i = 0; i < 4; i++) {

		event = cpuc->events[i];

		if (event)

			x86_perf_event_update(event);

	}



		for (i = 0; i < 3; i++) {

			struct perf_event *event = cpuc->events[i];

	for (i = 0; i < 4; i++) {

		wrmsrl(MSR_ARCH_PERFMON_EVENTSEL0 + i, nhm_magic[i]);

		wrmsrl(MSR_ARCH_PERFMON_PERFCTR0 + i, 0x0);

	}



			if (!event)

				continue;

	wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0xf);

	wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0x0);



	for (i = 0; i < 4; i++) {

		event = cpuc->events[i];



		if (event) {

			x86_perf_event_set_period(event);

			__x86_pmu_enable_event(&event->hw,

					ARCH_PERFMON_EVENTSEL_ENABLE);

		} else

			wrmsrl(MSR_ARCH_PERFMON_EVENTSEL0 + i, 0x0);

	}

}



static void intel_pmu_nhm_enable_all(int added)

{

	if (added)

		intel_pmu_nhm_workaround();

	intel_pmu_enable_all(added);

}

arch/x86/kernel/kprobes.c

+22 −3
Original line number Diff line number Diff line
@@ -709,6 +709,7 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs) 
	struct hlist_node *node, *tmp;

	unsigned long flags, orig_ret_address = 0;

	unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline;

	kprobe_opcode_t *correct_ret_addr = NULL;



	INIT_HLIST_HEAD(&empty_rp);

	kretprobe_hash_lock(current, &head, &flags);
@@ -740,14 +741,34 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs) 
			/* another task is sharing our hash bucket */

			continue;



		orig_ret_address = (unsigned long)ri->ret_addr;



		if (orig_ret_address != trampoline_address)

			/*

			 * This is the real return address. Any other

			 * instances associated with this task are for

			 * other calls deeper on the call stack

			 */

			break;

	}



	kretprobe_assert(ri, orig_ret_address, trampoline_address);



	correct_ret_addr = ri->ret_addr;

	hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {

		if (ri->task != current)

			/* another task is sharing our hash bucket */

			continue;



		orig_ret_address = (unsigned long)ri->ret_addr;

		if (ri->rp && ri->rp->handler) {

			__get_cpu_var(current_kprobe) = &ri->rp->kp;

			get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;

			ri->ret_addr = correct_ret_addr;

			ri->rp->handler(ri, regs);

			__get_cpu_var(current_kprobe) = NULL;

		}



		orig_ret_address = (unsigned long)ri->ret_addr;

		recycle_rp_inst(ri, &empty_rp);



		if (orig_ret_address != trampoline_address)
@@ -759,8 +780,6 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs) 
			break;

	}



	kretprobe_assert(ri, orig_ret_address, trampoline_address);



	kretprobe_hash_unlock(current, &flags);



	hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {

tools/perf/Makefile

+10 −4
Original line number Diff line number Diff line
@@ -5,6 +5,12 @@ endif 
# The default target of this Makefile is...

all::



ifneq ($(OUTPUT),)

# check that the output directory actually exists

OUTDIR := $(shell cd $(OUTPUT) && /bin/pwd)

$(if $(OUTDIR),, $(error output directory "$(OUTPUT)" does not exist))

endif



# Define V=1 to have a more verbose compile.

# Define V=2 to have an even more verbose compile.

#
@@ -931,15 +937,15 @@ $(OUTPUT)common-cmds.h: $(wildcard Documentation/perf-*.txt) 
	$(QUIET_GEN). util/generate-cmdlist.sh > $@+ && mv $@+ $@



$(patsubst %.sh,%,$(SCRIPT_SH)) : % : %.sh

	$(QUIET_GEN)$(RM) $@ $@+ && \

	$(QUIET_GEN)$(RM) $(OUTPUT)$@ $(OUTPUT)$@+ && \

	sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \

	    -e 's|@SHELL_PATH@|$(SHELL_PATH_SQ)|' \

	    -e 's|@@PERL@@|$(PERL_PATH_SQ)|g' \

	    -e 's/@@PERF_VERSION@@/$(PERF_VERSION)/g' \

	    -e 's/@@NO_CURL@@/$(NO_CURL)/g' \

	    $@.sh >$@+ && \

	chmod +x $@+ && \

	mv $@+ $(OUTPUT)$@

	    $@.sh > $(OUTPUT)$@+ && \

	chmod +x $(OUTPUT)$@+ && \

	mv $(OUTPUT)$@+ $(OUTPUT)$@



configure: configure.ac

	$(QUIET_GEN)$(RM) $@ $<+ && \

tools/perf/feature-tests.mak

+1 −1
Original line number Diff line number Diff line
@@ -113,7 +113,7 @@ endef 
# try-cc

# Usage: option = $(call try-cc, source-to-build, cc-options)

try-cc = $(shell sh -c						  \

	'TMP="$(TMPOUT).$$$$";			 		  \

	'TMP="$(OUTPUT)$(TMPOUT).$$$$";				  \

	 echo "$(1)" |						  \

	 $(CC) -x c - $(2) -o "$$TMP" > /dev/null 2>&1 && echo y; \

	 rm -f "$$TMP"')